This kind of reminds me of the cat in the microwave, specifically the case of Mrs. Smith in 1983.
The point is, you expect the product to work in such a way. Mostly because a number of similar products work like that, i.e. if you minimize them for hours and then open them up, they work (although the opposite is not as uncommon as you might think).
Mrs. Smith knew from her experience, that drying her cats in the oven wouldn't harm them (presuming some caution of course). More precisely from experience she had with all the ovens she tried. She then assumed it would be the same for the microwave oven she was given. This assumption was wrong. Microwaves are not designed to dry cats. Neither are conventional ovens. They just happen to not kill the cat in the process as a side effect of the physical processes they employ to generate heat.
Now as a producer of microwaves, you could place a heating coil and number of sensors into the microwave. The latter would determine, whether the current content is a cat and use the coil instead of microwaves.
In the same manner, that one could produce a microwave suitable to dry cats, Blizzard could create a version of SC2 that is suitable to stay in minimized state for extended periods of time.
Personally, I'd be willing to pay more money for a cat-drying-enabled microwave just for the fun of it (assuming there is a big cat-drying-suitability-logo in front I can proudly point at). But I wouldn't care for a game that can stay minimized for hours.
SC2 was designed to meet certain requirements. Your expectation is not part of those. You are free to measure SC2 in respect to your expectations. But whether or not Blizzard includes all of them in the scope of their requirements is ultimately their choice.
All you could really argue about is, that it's a design failure. Common sense dictates that unless a substantial fraction of the users are confused by the design or unhappy with it, it's good enough. I am sure if enough users state that they share your expectation, Blizzard would yield and include it in the design. This would render your problem an actual bug and Blizzard would fix it.